It’s difficult to overstate the important of this fight in the sport’s long and not always glorious narrative, from all the way back to John L. Sullivan’s days as the first gloved champion, right up to the modern days when a Floyd Mayweather Jnr can earn dozens of millions of dollars in just one fight seen around the globe.

Ali-Liston links those two extremes. It’s not too hard to imagine the glowering, sullen Liston – whose occupations prior to boxing were mugging and strike-breaking – battling Sullivan in a shabby barn with nervous punters hoping the action would be concluded before the local coppers arrived on the scene.

And what is Mayweather Jnr if not a latter-day version of Ali, a supreme fistic talent who has attracted as much attention for his out-of-the-ring activities as for his performances inside it? True, Ali’s impact on politics and culture will never be matched by Floyd, but that may be more a reflection on society as a whole. Nowadays top sportsmen are about promoting products, not changing the world.

But then Sonny (real name Charles) always did seem from a different age. He was born in 1932, the last world heavyweight champion to first see the light of day before World War II broke out. (Ernie Terrell, born April 1939, did hold the WBA version of the crown from 1965-67, but that was just a belt stripped from real champ Ali when he signed to meet Liston in an immediate rematch).

Sonny was one of 25 kids born to an illiterate sharecropper in Arkansas and his formal education was minimal; he was soon put to work in the fields, before escaping to big-city St Louis. Little wonder that the employment he found there would involve using his imposing physique to intimidate people.

Ali, born a decade later in 1942, didn’t exactly have a silver spoon in his mouth but he was fortunate to grow up in a post-war period of increasing peacetime prosperity. The expansion of television meant that becoming a sports star – and this included boxers – required more than just winning; a personality that exploded out of the goggle box and into people’s living rooms was essential if a performer wished to maximise the extent of his fame, and thus his earning power.

The young Cassius Clay, who changed his name after the first Liston victory, understood this perfectly while the man he replaced remained uncomfortable explaining himself in words. Not everything Ali said was profound or bears much scrutiny half a century later, but there can be no doubting the calculated braggadocio of the “Louisville Lip” opened up the world of huge paydays in fights broadcast around the world – a development from which Mayweather and his kind still benefit today.